Pelvic floor disorders are a class of abnormalities that affect the pelvic region of patients, and they afflict millions of women. The pelvic region includes various anatomical structures such as the uterus, the rectum, the bladder, and the vagina. These anatomical structures are supported and held in place by a complex collection of tissues, such as muscles and ligaments. When these tissues are damaged, stretched, or otherwise weakened, the anatomical structures of the pelvic region shift and in some cases protrude into other anatomical structures. For example, when the tissues between the bladder and the vagina weaken, the bladder may shift and protrude into the vagina, causing a pelvic floor disorder known as cystocele. Other pelvic floor disorders include vaginal prolapse, vaginal hernia, rectocele, enterocele, uterocele, and/or urethrocele.
Pelvic floor disorders often cause or exacerbate female urinary incontinence (UI). One type of UI, called stress urinary incontinence (SUI), effects primarily women and is often caused by two conditions—intrinsic sphincter deficiency (ISD) and hypermobility. These conditions may occur independently or in combination. In ISD, the urinary sphincter valve, located within the urethra, fails to close (or “coapt”) properly, causing urine to leak out of the urethra during stressful activity. In hypermobility, the pelvic floor is distended, weakened, or damaged. When the afflicted woman sneezes, coughs, or otherwise strains the pelvic region, the bladderneck and proximal urethra rotate and descend. As a result, the urethra does not close with sufficient response time, and urine leaks through the urethra. Often, treatments of stress incontinence are made without treating the pelvic floor disorders at all, potentially leading to an early recurrence of the stress incontinence.
UI and pelvic floor disorders, which are usually accompanied by significant pain and discomfort, are often treated by implanting a supportive sling in or near the pelvic floor region to support the fallen or shifted anatomical structures or more generally, to strengthen the pelvic region by promoting tissue ingrowth. Such slings may be made from a variety of materials, but are often made from a mesh material. A mesh may be placed, for example, under the urethra, close to the high-pressure zone with little or no elevation to the urethra. When abdominal pressure increases, such as from coughing, sneezing, or the like, the sling facilitates the collapse of the urethra as a mechanism for closing the urethra to inhibit urine leakage. As another example, a wider mesh may be placed under the bladder to prevent it from protruding into other anatomical structures such as the vagina.
Various methods exist for implanting and securing slings. Some methods use soft tissue anchors to secure the slings to specific locations within the patient. These methods require highly accurate sling length to insure the sling aligns with the appropriate anchoring locations while creating the correct balance of tension and slack under the urethra or prolapsed organ. Some securement methods rely on the intrinsic coarseness of the edges of the mesh material to adhere to the patient's tissue, requiring the sling to have a substantial length. However, many current procedures, such as transobturator (TOT) and single incision procedures, require a shorter sling.
After the sling is implanted, the mesh material of the sling stretches and becomes less resilient, losing its ability to collapse the urethra or support the prolapsed organ. Scar tissue may form around the sling, further securing the sling within the patient and facilitating urethral closure or prolapsed organ support, but the scar tissue formation may be impeded by the stretching of the mesh. Previous methods for strengthening the sling typically reduced or did not address the sling's ability to be secured within the patient.
There is need for a sling with prolonged mesh material resilience, improved stimulation of scar tissue ingrowth, and a stronger securement method that is less dependent on sling length.